Over the years audio/video editing systems have developed into complex and sophisticated arrangements for manipulating video and audio information recorded therewith in a desired fashion. In a typical editing system selected video or audio information from a plurality of different inputs is recorded on a record audio/video tape recorder under the careful control of an operator. The information to be recorded is typically contained in one or more of a plurality of source tape recorders but can also come from other input sources such as a microphone or video camera. A switcher coupled between the record tape recorder and the source tape recorders and any other input devices responds to editing commands to control the exact information recorded by the record tape recorder. Proper synchronization during the recording operation characterizing a typical editing process is maintained by reference to a coded reference track which accompanies each recording on tape and which identifies each frame of the recording. Such reference tracks typically involve the use of time code (recorded either directly on the reference track within the video tracks during the vertical interval, or a combination of both) as specified in various documents by the Society Of Motion Picture And Television Engineers (SMPTE) and the European Broadcasting Union (EBU).
In a typical editing operation the operator manipulates a keyboard while viewing a video monitor which provides a visual display of the video information being recorded on the record tape recorder. The keyboard is typically a designated keyboard, meaning that it is comprised of different keys representing specific editing functions. The keys may be arranged in an ASCII format or in any other format which is convenient. Keys arranged in the ASCII format are also designated by letters arranged in a conventional typewriter keyboard format so that the various different editing functions can be selected largely by feel and based on experience and memory, much in the same manner as an experienced typist types.
As editing systems have become more sophisticated and complex, the keyboards used therewith have grown larger and more confusing. It is not unusual, for example, to have an editing keyboard comprised of more than 100 keys, each representing a different editing function or type of function. As a result considerable time and experience are required with a given machine before the operator can perform editing functions quickly and efficiently. However, even in cases where the operator is experienced and totally familiar with a given editing system, there is an inherent problem with conventional editing systems in that the mechanical considerations imposed by a fixed keyboard with so many functions seriously detract from the creative aspects of editing. Time code representations of edit entry and exit points are typically relied upon rather than editing in accordance with the picture itself.
A further limitation of many conventional editing systems resides in the confinement of system intelligence to one central location. Those systems employing a central processor or other processing unit in conjunction with the editing functions typically concentrate limited processing equipment at one central location, thereby restricting future flexibility of a particular system.
Over the years various attempts have been made at improving the human-machine interface involved in editing. One such approach, for example, involves the use of a light pen. The pen is manipulated relative to a responding member to select certain editing functions, thereby reducing the number of buttons needed. At best, however, such systems replace keyboard buttons with the light pen, requiring that the operator pick up and handle the light pen with each operation.
Accordingly, it would be desirable to provide an editing system with improved human-machine interfacing so as to facilitate the artistic aspects and approach to video editing.
It would furthermore be desirable to provide an editing system capable of displaying different menus of editing functions to be chosen from by the operator.
It would furthermore be desirable to provide an editing system capable of accommodating varying numbers and types of information inputs.
It would still furthermore be advantageous to provide an editing system capable of intelligent operations at peripheral portions of such system in addition to a central portion of the system.